The present application claims priority from Australian Provisional Application No. 2002951399, filed 16 Sep. 2002 and Australian Provisional Application No. 2002951402, filed 16 Sep. 2002, the teachings of each of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to a vehicle alarm or immobiliser, and in particular a vehicle immobiliser or alarm of the type incorporating a coded key for verification of control signals used to disarm (and preferably also to arm) the immobiliser or alarm.
2. Background Art
In a vehicle security system the method of deactivating is almost always by means of a coded key. The coded key may be a radio remote, a proximity device or a contact type such as a plug which is inserted into a socket. In order to offer security the number of codes should be high. In most modem security systems taking into account various encryption methods, the number of different codes can effectively be in the billions. Often the coded key is provided as a binary code which is serially transmitted to an immobiliser or car alarm. In modem security systems a transmitted code can have 64 bits, and taking into account various encryption methods, the number of different codes can be in the billions. In addition there is a system of encryption which uses xe2x80x9ccode-hoppingxe2x80x9d, where the transmitted code has a portion thereof which increments by a predetermined amount determined by an algorithm in the coded key. The immobiliser responsive to the coded key incorporating the code-hopping technology includes a processor which is able to predict ahead a large number of increments, so that the immobiliser remains responsive to the coded key in the event that the coded key is caused to transmit several increments out of range of the immobiliser.
The security system is, in normal use, responsive to a unique allocated user code, so that the security system can be disabled and enabled by the owner of the vehicle in which it is installed. This user code is determined and programmed into the coded key during manufacture, and into the security system either during manufacture or alternatively the security system can learn the user code from the coded key, by placing the security system into a learning mode.
Motor vehicle dealers usually have many cars at one time in their car yard. The typical practice is to have the keys to the vehicles stored in a central secure location, such as in the sales office. Staff wishing to demonstrate a vehicle to a potential customer must retrieve the keys and any coded key remote control (or other type of coded key) for the vehicle beforehand.
It is an object of this invention to provide a system and method that can provide security to vehicles in a car yard or like establishment, and obviate the above difficulty.
Throughout the specification, unless the context requires otherwise, the word xe2x80x9ccomprisexe2x80x9d or variations such as xe2x80x9ccomprisesxe2x80x9d or xe2x80x9ccomprisingxe2x80x9d, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
The applicant has provided an improvement in security systems for vehicles which provides in a security system for one or more of a plurality of available supervisor codes, which allows one or more unique supervisor codes to be allocated to a motor vehicle dealer. The security system with unique supervisor code(s) allocated, is then responsive to respective supervisor code coded key(s), with limited permissions for control of security system features. This allows one or more unique supervisor codes to be allocated to a motor vehicle dealer.
The applicant has provided, in a preferred arrangement, an improvement in security systems for vehicles which provides in a security system a master code having full permissions for control of security system features using a master code coded key, a second tier of a plurality of supervisor codes from which one or more may be allocated and enabled, the enabled supervisor code(s) having limited permissions for control of security system features using one or more supervisor code coded keys. This also allows a unique second tier supervisor code to be allocated to a motor vehicle dealer.
The security system also of course, includes facility for one of a plurality of possible user codes to be allocated and enabled, for normal use by a final consumer/user using a user code coded key.
Either arrangement described above allows a single unique supervisor coded key to be used to disable all of the second tier supervisor code keyed vehicle security systems fitted to vehicles on the vehicle dealer car lot. This feature saves considerable time for a car lot operator wanting to demonstrate a car, as the ignition keys can safely be left in the vehicles.
Either arrangement may include a feature whereby the enabling of a supervisor code disables a user code, and vice versa.
In accordance with one aspect of the invention there is provided a security system including a security device arranged to exert control over a predetermined function, said security device being responsive to a coded key to exert control over said predetermined function, said coded key and said security device communicating using a data string of a predetermined format, wherein said data string includes a predetermined portion thereof having settable values, wherein said settable values when within a first predetermined range of values correspond to user codes assigned to user coded keys for said security device, and said settable values when within a second predetermined range of values correspond to supervisor codes assigned to supervisor coded keys for said security device, and said settable values when within a third predetermined range of values correspond to user codes assigned to master coded keys for said security device, wherein said security system includes programming means allowing said security device to be programmable to be responsive to one or more said supervisor coded keys and/or one or more said user coded keys, or one or more of said user coded keys only, wherein said supervisor coded keys have an intermediate level of access to said programming means between the level of access of said master coded keys and said user coded keys.
Typically, the supervisor coded keys can be provided to authorised personnel, while the user coded keys would be provided to users having more limited access. For example, in security systems such as vehicle immobilisers, supervisor coded keys could be provided to car sales staff, while user coded keys could be provided to customers who ultimately purchase the vehicle. In such an arrangement, user coded keys are always coded specifically for a particular security device. The master coded keys have a greater level of access than the supervisor coded keys, and are usually restricted to the security system manufacturer, seller, and installer. It should be understood that there may be one or more master coded keys.
Preferably said security system includes programming means allowing said security device to be programmable to be responsive exclusively to one or more said supervisor coded keys, or exclusively to one or more of said user coded keys only.
The second range of values may be conveniently limited to 65534 possible values. Within the data string there are a number of combinations available, based on other portions of code outside of the second range making up the remainder of the data string. In motor vehicle dealerships, this allows for 65534 different possible dealers codes, and a plurality of different remote controls incorporating identical second strings, for use by staff within the dealership.
In accordance with a second aspect of the invention there is provided a method of providing security against theft to a plurality of vehicles at a site, said method including steps of providing a security system as hereinbefore described, the security system comprising a plurality of security devices for selectively immobilising and enabling operation of vehicles, and installing said security devices in vehicles at said site, wherein all of said security devices are selectably responsive to one or more coded keys specific to said site.
Preferably said security devices are selectably responsive to said coded keys by being programmed to recognise code transmitted thereby.
Also in accordance with a second aspect of the invention there is provided a method of providing security against theft to a plurality of vehicles at a site, said method including steps of providing a security system as hereinbefore described, allocating said supervisor coded keys with supervisor codes specific to said site, installing a said security device in each of said vehicles at said site, and actuating said programming means to program each said security device to be responsive to said supervisor coded keys allocated to said site for selectively immobilising and enabling operation of vehicles, wherein all of said security devices are selectably responsive to one or more supervisor coded keys allocated to said site.
Preferably said security devices are responsive to said supervisor coded keys to actuate said programming means to program said security device to be solely responsive to code transmitted by one or more specific said user coded keys.
Preferably said security devices are incorporated in relays used to control a circuit essential for operation of the vehicle. An example of such a relay is described in the applicant""s co-pending patent application PCT/AU01/01075, the contents of the specification for which are incorporated herein by cross-reference.
With this arrangement, a site can be provided with one or more coded keys, and security devices, responsive to the coded keys, for fitting into vehicles. With two or more adjacent sites having the same system in place, the security devices only respond to coded keys at the correct site.